Buggy code:
public class Generator { private static final Factory _factoryJST = new JST . Helper . Factory ( ) ; private static final JSTProperties _jstProp = new JST . Helper . JSTProperties ( ) ; private static final String _largestJSNumber = "9007199254740992" ; private final Configs _configs ; private final GenLogic _logic ; private final ExecFlow _flowLevel ; private final StringCounter _counterVar = new StringCounter ( "v%d" ) ; private final StringCounter _counterFunc = new StringCounter ( "f%d" ) ; private final StringCounter _counterLoopVar = new StringCounter ( "loop_var%d" ) ; private final StringBuilder _verboseString = new StringBuilder ( ) ; private Program _program ; private Context _rootContext ; public Generator ( Configs configs , String seed , ExecFlow flowLevel ) { } public Program createProgram ( ) { } private void initNewProgram ( ) { } public String getVerboseOutput ( ) { } private void trace ( String str ) { } private void traceIn ( String str ) { } private void traceRemoveLine ( ) { } private void traceOut ( ) { } private Comment generateHeader ( ) { } private Comment generateFooter ( ) { } If createIf ( Context context , createParams params ) { } While createWhile ( Context context , createParams params ) { } DoWhile createDoWhile ( Context context , createParams params ) { } For createFor ( Context context , createParams params ) { } ForEach createForEach ( Context context , createParams params ) { } Switch createSwitch ( Context context , createParams params ) { } CaseBlock createCaseBlock ( Context context , createParams params ) { } Case createCase ( Context context , createParams params ) { } FunctionExp createFunctionExp ( Context context , createParams params ) { } FunctionDef createFunctionDef ( Context context , createParams params ) { } private List < Identifier > getFunctionParametersList ( Context context , Integer paramsNum ) { } VarDecleration createVarDecleration ( Context context , createParams params ) { } VarDeclerator createVarDeclerator ( Context context , createParams params ) { } Continue createContinue ( Context context , createParams params ) { } Break createBreak ( Context context , createParams params ) { } Return createReturn ( Context context , createParams params ) { } StatementsBlock createStatementsBlock ( Context context , createParams params ) { traceIn ( "StatementsBlock" ) ; StatementsBlock stmtBlock = new StatementsBlock ( ) ; stmtBlock . addStatement ( new Comment ( ( "block<seq2seq4repair_space>id:<seq2seq4repair_space>" + ( stmtBlock . getUniqueId ( ) ) ) ) ) ; if ( _flowLevel . isA ( EXTENSIVE ) ) { <START_BUG> Call debugCall = new Call ( getApiMethod ( PRINT ) , new LiteralString ( ( "block<seq2seq4repair_space>" + ( stmtBlock . getUniqueId ( ) ) ) ) ) ; <END_BUG> debugCall . setNoneRandomBranch ( ) ; stmtBlock . addStatement ( debugCall ) ; } AbsStatement firstStatement = StatementBlockParams . getFirstStatement ( params ) ; if ( firstStatement != null ) { stmtBlock . addStatement ( firstStatement ) ; } int size = 0 ; if ( ( _logic . getDepth ( ) ) < ( _configs . valInt ( MAX_JST_DEPTH ) ) ) { double factorDepth = Math . pow ( _configs . valDouble ( FACTOR_DEPTH ) , _logic . getDepth ( ) ) ; double lambda = ( _configs . valDouble ( STMTS_BLOCK_SIZE_LAMBDA ) ) // factorDepth ; size = StdRandom . expCeiled ( lambda ) ; } stmtBlock . addStatement ( _logic . generateStatement ( context , null , size ) ) ; traceOut ( ) ; return stmtBlock ; } Assignment createAssignment ( Context context , createParams params ) { } CompoundAssignment createCompoundAssignment ( Context context , createParams params ) { } Call createCall ( Context context , createParams params ) { } MemberExp createMemberExp ( Context context , createParams params ) { } ObjectExp createObjectExp ( Context context , createParams params ) { } ArrayExp createArrayExp ( Context context , createParams params ) { } Identifier createIdentifier ( Context context , createParams params ) { } This createThis ( Context context , createParams params ) { } OperationExp createOperationExp ( Context context , createParams params ) { } Literal createLiteral ( Context context , createParams params ) { } LiteralString createLiteralString ( Context context , createParams params ) { } LiteralNumber createLiteralNumber ( Context context , createParams params ) { } private AbsWhileLoop commonWhile ( Class < ? extends AbsWhileLoop > classWhile , Context context ) { } private List < AbsStatement > getLoopCounterStmts ( Context context ) { } private int getRandomLoopIterationsLimit ( ) { } private Identifier createVarIdentifierNotInCurrentScope ( Context context , createParams params ) { } private boolean isLegalNum ( StringBuilder strNum ) { } private List < ProgramUnit > generatePrintVarsSection ( ) { } private Call newOutputStatement ( String str ) { } private Call newOutputStatement ( AbsExpression expr ) { } private MemberExp getApiMethod ( ApiOptions apiMethod ) { } }

Fix:
Call debugCall = new Call ( getApiMethod ( TRACE_DEBUG ) , new LiteralString ( ( "block<seq2seq4repair_space>" + ( stmtBlock . getUniqueId ( ) ) ) ) ) ;